Fix undo shortcut in Undoing.md
We fixed this recently in the Readme (see 7a3bae4de1f7), but forgot to update this.
S
Stefan Haller committed
9ae76d7eec2800957c37e78bc00be4c3ab503135
Parent: 87e6959
We fixed this recently in the Readme (see 7a3bae4de1f7), but forgot to update this.